形状记忆合金混杂复合材料层合板变刚度调控机制

Variable Stiffness Control Mechanism of Shape Memory Alloy Hybrid Composite Laminates

形状记忆合金混杂复合材料(SMAHC)是一种能够主动变化刚度的智能复合材料。为了研究形状记忆合金(SMA)对SMAHC层合板刚度调控的影响,对分布式、模块化地植入SMA的层合板进行三点压弯实验。以SMA数量、单层中SMA排布位置与SMA预应变作为3个独立变量进行正交实验设计,测试了不同试样在不同温度下的刚度值,以研究如何有效地实现刚度调控。采用等效热膨胀法建立SMAHC层合板的有限元模型与实验结果进行对比,总结了SMAHC层合板的变刚度调控机制。分析结果表明,SMA非对称排布的层合板比SMA对称排布的层合板平均刚度提升16.67%;植入8段SMA的层合板比植入4段SMA的层合板平均刚度提升15.26%;通过调整SMA的温度,可以精准地实现SMAHC层合板的刚度调控;模块化、分布式的植入方式能够改变SMAHC层合板整体的应力分布,提升层合板刚度调控精度、降低SMA纤维用量,而且能保证个别SMA失效后层合板整体仍然有一定的变刚度能力。

Shape memory alloy hybrid composite(SMAHC)is an intelligent composite material that can actively change stiffness.In order to study the effect of shape memory alloy(SMA)on the stiffness regulation of SMAHC laminated plates,three-point bending experiments were carried out on the laminated plates with distributed and modular SMA implants.The orthogonal experimental design was carried out with the number of SMA,the arrangement position of SMA in the single layer and the pre-strain of SMA as three independent variables.The stiffness values of different samples at different temperatures were tested to study how to effectively realize the stiffness control.The finite element model of SMAHC laminates was established by equivalent thermal expansion method and compared with the experimental results.The variable stiffness control mechanism of SMAHC laminates was summarized.The analysis results show that the average stiffness of the laminated plate with asymmetric SMA arrangement is 16.67%higher than that of the laminated plate with symmetrical SMA arrangement.The average stiffness of the laminates implanted with 8 SMA segments is 15.26%higher than that of the laminates implanted with 4 SMA segments.By adjusting the temperature of SMA,the stiffness control of SMAHC laminates can be accurately realized.The modular and distributed implantation method can change the overall stress distribution of SMAHC laminate,improve the stiffness control accuracy of the laminate,reduce the amount of SMA fiber,and ensure that the laminate still has a certain variable stiffness after individual SMA failure.